1. Field of the Invention
The present invention relates to a dimpling device for dimpling the surroundings of rivet holes; and more particularly to a dimpling device for dimpling the surroundings of rivet holes preformed in workpieces into dish shapes to fasten superimposed workpieces with a flush rivet.
2. Description of the Background Art
In the background art, a flush rivet having a frustoconical head that is used as a rivet for fastening a skin of an airplane to an inner frame of the airplane suffers from a low air resistance. However, the present inventor has determined that it is necessary to dimple the surroundings of rivet holes when using this type of flush rivet. The rivet holes are preformed in the skin and the inner frame that are to be fastened together, e.g., preformed into dish shapes so as to form a recess which receives the frustoconical head of the flush rivet.
A flush rivet dimpling device of the background art is shown and described in U.S. Pat. No. 4,858,289 to Speller, Sr., the entire contents of which are hereby incorporated by reference.